I wrote that post a couple of years ago, and haven't thought much of the subject in the intervening time. What I'm synthesizing there is an idea of Badian's, that Antony may well have been involved in the conspiracy, although I don't know whether he actually published it since it was all highly conjectural speculation--it was more like a personal opinion of his. Our texts preserve a number of details with regard to Antony's conduct before, during, and after the conspiracy that are rather odd. A great deal of this, however, comes from later rhetoric--Cicero, for example, accused Antony in the Philippics of being involved in an anti-Caesarian plot. Accusations like these were not uncommon in the decades following Caesar's death and Antony's decline, to the point that even within his own lifetime it was hard to separate the real Antony from his rhetorical counterpart. In only one example, Antony's supposed alcoholism, so frequently used as rhetorical ammunition against him, became so constantly referred to that Antony had to publish the de sua ebrietate in order to attempt to prove that his rhetorical shadow was not the same as his actual person. The oddities in Antony's conduct and possible involvement unfortunately derive from vague references and a single source tradition--a good one, but if we rely solely on Cicero we risk treating all kinds of polemic rhetoric as fact.